/*
 * Tencent is pleased to support the open source community by making Angel available.
 *
 * Copyright (C) 2017-2018 THL A29 Limited, a Tencent company. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 *
 * https://opensource.org/licenses/Apache-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 *
 */

package com.tencent.angel.graph.psf.neighbors.samplebyaliastable.initaliastable;

import com.tencent.angel.ml.matrix.psf.update.base.PartitionUpdateParam;
import com.tencent.angel.ml.matrix.psf.update.base.UpdateFunc;
import com.tencent.angel.ps.storage.matrix.ServerMatrix;
import com.tencent.angel.ps.storage.partition.RowBasedPartition;
import com.tencent.angel.ps.storage.vector.ServerLongAnyRow;
import com.tencent.angel.graph.psf.neighbors.samplebyaliastable.samplealiastable.NeighborsAliasTableElement;
import it.unimi.dsi.fastutil.longs.Long2ObjectMap;
import it.unimi.dsi.fastutil.objects.ObjectIterator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class InitNeighborAliasTable extends UpdateFunc {
    private static final Logger LOG = LoggerFactory.getLogger(InitNeighborAliasTable.class);

    /**
     * Create a new UpdateParam
     */
    public InitNeighborAliasTable(InitNeighborAliasTableParam param) {
        super(param);
    }

    public InitNeighborAliasTable() {
        this(null);
    }

    @Override
    public void partitionUpdate(PartitionUpdateParam partParam) {
        PartInitNeighborAliasTableParam param = (PartInitNeighborAliasTableParam) partParam;
        ServerMatrix matrix = psContext.getMatrixStorageManager().getMatrix(partParam.getMatrixId());
        RowBasedPartition part = (RowBasedPartition) matrix
                .getPartition(partParam.getPartKey().getPartitionId());
        ServerLongAnyRow row = (ServerLongAnyRow) part.getRow(0);

        ObjectIterator<Long2ObjectMap.Entry<NeighborsAliasTableElement>> iter = param.getNodeId2Neighbors().long2ObjectEntrySet().iterator();

        row.startWrite();
        try {
            while (iter.hasNext()) {
                Long2ObjectMap.Entry<NeighborsAliasTableElement> entry = iter.next();
                NeighborsAliasTableElement element = entry.getValue();
                if (element == null) {
                    row.set(entry.getLongKey(), null);
                } else {
                    row.set(entry.getLongKey(), new NeighborsAliasTableElement(element.getNeighborIds(), element.getAccept(), element.getAlias()));
                }
            }
        } finally {
            row.endWrite();
        }
    }
}